LOS ANGELES (Reuters) - "Keeping Up With The Kardashians" star Kourtney Kardashian, sister of Kim and Khloe, gave birth to a daughter over the weekend, adding to the reality TV family's growing brood.

"Welcome to the world, Penelope Scotland Disick! Kourtney gave birth to a beautiful baby daughter on Sunday, and the whole family is so thrilled to finally meet her! She is absolutely perfect!" Kim Kardashian posted on her official website on Sunday.

This is the second child for Kourtney Kardashian, 33, and fiance Scott Disick, 29, who have a two-year-old son, Mason.

The Kardashian family have become a dominant force in U.S. reality television over the past few years, starring in four shows on cable network E!, three of which were created by Ryan Seacrest.

Kim Kardashian, 31, is one of the highest paid reality stars on U.S. television, with her 2010 earnings estimated at $6 million by news website The Daily Beast.

Her family's net worth was last estimated at $65 million in 2010 by trade magazine The Hollywood Reporter.

(Reporting By Piya Sinha-Roy; Editing by Bob Tourtellotte)